Set 2 racks in the middle and upper thirds of the oven and preheat to 350 degrees F.

In a medium bowl, sift the flour, baking powder, baking soda, and salt together. Stir in the oatmeal.

In a large bowl, beat the butter, brown sugar together for 30 seconds until blended. Beat in the egg until smooth and barely fluffy. With mixer running on medium high, drizzle in the maple syrup and vanilla until incorporated. Turn the mixer sown to its lowest setting and gradually add the dry mixture. Blend just to combine, then mix in the chocolate chips.

Drop walnut-sized balls of dough onto a parchment-lined cookie sheet at 3-inch intervals. With moistened fingers, flatten and round out the cookies a little. Bake for 9 minutes, turning the pan once for even baking. The cookies are done when they are lightly browned on top. Set the cookie sheets on a rack to cool.